"Computing is the only profession in which single mind is obliged to span the distance from a bit to a few hundred megabytes, a ratio of 1 to 10^9, or nine orders of magnitude. Compared to that number of semantic levels, the average mathematical theory is almost flat. By evoking the need for deep conceptual hierarchies, the automatic computer confronts us with a radically new intellectual challenge that has no precedent in our history." - (Edgar Djikstra 1989)
Of course software has become even more complex since 1989, and Dijkstra's ratio of 1 to 10^9 could easily be 1 to 10^15 today.